The present invention relates to a slider, to be applied into a magnetic disk apparatus, and has a function of adjusting a distance between the magnetic disk and a magnetic head thereof.
Conventionally, for example, in Japanese Patent Laying-Open No. Hei 5-20635 (1993) is already known a magnetic head, having a thin-film magnetic head device, in which a lower portion magnetic pole, a thin-film coil being formed insulating through an insulating material layer, an upper magnetic pole, and a protection layer are formed, sequentially, on a substrate. In such the magnetic head, a thin-film resistor is formed within an inside of the layer of insulating material mentioned above, so that a tip portion of the magnetic pole can expand thermally, while conducting electricity therethrough, thereby to project or protrude it from.
Among recording elements to be used for recording, or reproducing elements to be used for reproducing, or recording/reproducing elements, which enables both, i.e., recording and reproducing (hereinafter, they are called by a “recording/reproducing elements”, collectively), some of them are weak against heat load thereupon. For example, a reproducing element applying the magneto-resistitve effect (i.e., MR effect) therein, now being mainly used, has a problem that it is weak against the heat load, and it is shortened in the life-time thereof if being exposed for a long time under high temperature condition. If trying to rise up an efficiency of converting electric power into an a mount of deformation at the maximum thereof, in particular, in a heat or thermal actuator relating to such the conventional art mentioned above, it is most suitable that a heating device is located in a very vicinity of the recording/reproducing elements, near to a surface of an air or pneumatic bearing (hereinafter, being called by a “floating or flying surface”). However, if the heating device is located in the vicinity of the recording/reproducing device, there is a possibility that the lifetime of the recording/reproducing element may be shortened due to the heating thereof.
Also, with the heat actuator, a flying height is held after reaching into an equilibrium condition, therefore it is necessary to supply the electric power into the heat or thermal actuator. For this reason, there is a necessity of developing a thermal actuator having a good efficiency of converting the electric power into an amount of deformation, thereby reducing consumption of electric power. In particular, for the magnetic disk to be installed in equipments being portable, there is a strict restriction in the consumption of electric power, therefore it will come up to be a big problem.